SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d87e5b7fab230c96fc0d7205b9f7f8250d7d18a217ba84298ab758c8730fb52' 
  AND token = 'MyqKuPBEEGHf3LtLwPy4+pTbL+yum3lzjcxgyzvzNtg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}